Superconductivity in the doped topological insulator CuxBi2Se3 under high pressure

We report a high-pressure single crystal study of the topological superconductor CuxBi2Se3. Resistivity measurements under pressure show superconductivity is depressed smoothly. At the same time the metallic behavior is gradually lost. The upper-critical field data Bc2(T) under pressure collapse onto a universal curve. The absence of Pauli limiting and the comparison of Bc2(T) to a polar-state function point to spin-triplet superconductivity, but an anisotropic spin-singlet state cannot be discarded completely.